Science Siftings

New Zealand Tablet, 28 January 1915, Page 51

Science Siftings

By ‘ Volt.’

Epidemics.

Where does disease come from ? This has long been a i important question, and also as to when it first makes its appearance in a given locality. It is now clearly established that all sorts of diseases may occur spontaneously, and appear as epidemics, without being propagated by contagion after the first outbreak. All known contagious diseases may be produced originally under certain atmospheric and sanitary conditions without contact with a diseased person. Smallpox, and even plague, has arisen spontaneously all over Europe and Asia, and these, as well as all contagious diseases, appear to possess the power of self-propagation under favorable conditions.

New Cinema Apparatus.

A cinematograph apparatus entirelv free from the scintillations which are so tiring to the eyes of spectators, has been devised by the French scientist, M. Edouard Belin, well known for his discoveries in connection with tele-photography, after long research. His apparatus, which is of a highly complex nature, reproduces life exactly and continuously. The film does not appear as a series of separate pictures rapidly succeeding each other. Thus, marching troops and ceremonial processions do not have the spasmodic, jerky action inevitable with present cinematographs, because, if turned slowly, the scintillation would become unbearable. M. Belin has demonstrated the qualities of his apparatus to a company of French scientists with great success.

Wireless Telephone

An interesting reference to the time, not far ahead, when wireless telephony for commercial purposes will be possible, is made in the report of the directors of the Marconi Company. Rapid progress, says the board, lias been made in the development of wireless telephone apparatus, and the company has recently introduced a practical and commercial set for moderate distances. Further important developments are proceeding, and it is contemplated that apparatus will shortly be available for the transmission of speech over considerable distances. The development of this new means of communication

should, it is declared; add considerably to the earning powers of the company. °

Monster Fog Horn.

Many lighthouses possess fog signals for warning the mariner of the presence of rocks and other dangers in foggy weather. The larger ones are so powerful that their blasts can be heard 25 to 30 miles out at sea. Most of them are worked by compressed air, a gas engine of perhaps 20 to 25 horse-power being brought into requisition for this purpose. The siren is blown periodically every 70, 80, or 90 seconds or so, the actual blast lasting perhaps about two to three seconds. It means that while the siren is running, in the case of the larger apparatus, something like 500 horse-power is being expended in the production of sound !

What ‘ S.O.S.’ Means.

In talking with the wireless operator, many ship passengers ask the meaning of the three letters used in the distress signal, ‘ S.O.S.' There seems to be a general opinion that the letters are the abbreviation for three separate words with a definite meaning. Persons of an imaginative trend will tell you that the letters stand for ‘ Save our ship,’ ‘ Send out succor/ ‘ Sink or swim/ or some such meaning. The letters signify nothing but that a ship is in distress and in need of assistance. The call is used by all nations as a universal code, so that any wireless operator, regardless of the language he speaks, can immediately intercept the call of distress. Inasmuch as the call is in use by all countries, it can be seen that the signal can have no meaning in any language. The character of the code makes it a call that can be picked out easily from other signals, being composed of three dots, three dashes, three dots.